After posting this whilst looking at the file names in my Seeder folder I realised this might be due to the Class and/or Filename? Perphaps Laravel assumes that if there's no "Create" in their names that there won't be a reason to run the down method?

[edit]
Change the class to CreateViewsAndAddTriggersTable and the file to 2018_10_07_175757_create_views_and_add_triggers_table.php to no avail. So much for that theory.